Several processes are known in the art for the production of polylactams by performing a polymerization of higher lactam monomers in the presence of catalysts e.g. sodium amide, sodium metal, waterfree ethanol, carbon dioxide and so on, and furthermore in the presence of an activator e.g. isocyanates or substituted lactams and so on. We e.g. refer to German Offenlegungsschrift No. 25 07 549.
If very strong basic substances are used, and especially if sodium amide is employed, then it is generally necessary to perform all working steps in an inert gas atmosphere. This is necessary because otherwise some of the above mentioned bases would react with the moisture present in the air forming undesired by-products. It has been found that a catalyst containing impurities and by-products can materially with interfere the polymerization process described in the German Offenlegungsschrift No. 25 07 549 and can also result in the deterioration of the properties of the prepared polymers of the higher lactams.
It is rather dangerous to work with larger amounts of sodium amide or similar bases because said substances are poisonous and may given rise to risk of to explosions and are furthermore extremely sensitive to traces of water. This results in the said substances being difficult to handle, especially if applied in industry.
If the substances in question are applied in industry then complicated and expensive apparatus has to be used which result in higher costs of production.
A further difficulty is that the above stated strong bases can only be difficultly dosed if the medium is not completely free of water.
A further essential point is that acids formed must be removed practically completely because otherwise the presence of acids might result in further difficulties.